Theory of quantum transport in Josephson junctions with a ferromagnetic insulator
Автор(и)
Shiro Kawabata
Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
Yasuhiro Asano
CREST, Japan Science and Technology Corporation (JST), Kawaguchi, Saitama 332-0012, Japan
We investigate the Josephson transport through ferromagnetic insulators (FIs) by taking into account the band structure of FIs explicitly. Using the recursive Green's function method, we found the formation of a π-junction in such systems. Moreover the atomic-scale 0–π oscillation is induced by increasing the thickness of FI and its
oscillation period is universal, i.e., just single atomic layer. Based on these results, we show that stable π-state
can be realized in junctions based on high-Tc superconductors with La2BaCuO5 barrier. Such FI-based Josephson junctions may become an element in the architecture of future quantum computers.